Aircraft windows are generally secured to the underlying support by means of clips which attach to stuctural members. Ideally, such clips are lightweight, strong and promote an airtight seal between the window and the support which is not affected by pressure differentials between the inside and outside of the aircraft.
FIG. 4 shows a prior art overbeam clip 52 for attaching windows to aircraft hatches. Clip 52 has a u-shaped backbone segment 54 with inwardly curving beam end 56 and window end 58. Tang 60 overhangs inner window pane 62. Pane 62 is set in seal 64 with outer pane 66. Clip 52 is screwed into support beam 68 by means of screw 70. Spacer 72 is inserted between clip 52 and beam 68.
Prior art clip 52 and clips with similar backbone structures such as that shown in U.S. Pat. No. 4,793,108, assigned to the assignee hereof, have a number of undesirable properties. For example, the clip must have the exact proper length to form a tight, but not too tight, seal with the window. Because the length of the clip is so critical, several different clips and spacers may be needed for the same aircraft. It is also possible for the installer to tighten the clip down too hard and crack the window or not hard enough to form a tight seal. If a clip loosens, it can chafe the window surround, beam or window by wobbling or rotating around the mounting screw.
U.S. Pat. No. 4,611,850 to Fujikawa shows a clip, detail 18, for attaching a window to an automobile in conjunction with a second clip, detail 17A, a rubber gasket, detail 16, and a screw, detail 15A. U.S. Pat. No. 3,094,738 shows a biased spring with a spacer for a door closer. U.S. Pat. No. 2,989,338 shows a clip for retaining a window gasket in place in an automotive vehicle, which is similar to the prior art clip described above.
None of these prior art clips, nor any combination of them, suggests a clip for aircraft window panes that eliminates the drawbacks noted above.